Measurement of Out-of-plane Dynamic Deformations by Digital Speckle Pattern Interferometry

Abstract

In this paper, measurement of dynamic deformations in a rectangular plate fixed at one end, using digital speckle pattem interferometry (DSPI), has been prese,nted. To improve the measurement accuracy,
a new filtering scheme has been developed. This scheme is based on the combination of average/ median filtering and Symlet wavelet filtering which enhances the signal-to-noise ratio in the speckle
interferogram obtained from the DSPI. Experimental results show that this filtering scheme is quite effective in improving signal-to-noise ratio of the speckle .interferogram. The measurements by DSPI
and accelerometer are in good agreement. The DSPI technique can be implemented for measuring the large deformations as well.